--- code/trunk/ChangeLog 2007/02/24 21:40:37 75
+++ code/trunk/ChangeLog 2007/11/17 16:53:53 272
@@ -1,6 +1,1446 @@
ChangeLog for PCRE
------------------
+Version 7.5 12-Nov-07
+---------------------
+
+1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
+ values in parens when parsing an RE using the C++ wrapper."
+
+2. Negative specials like \S did not work in character classes in UTF-8 mode.
+ Characters greater than 255 were excluded from the class instead of being
+ included.
+
+3. The same bug as (2) above applied to negated POSIX classes such as
+ [:^space:].
+
+4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
+ defined or documented. It seems to have been a typo for PCRE_STATIC, so
+ I have changed it.
+
+5. The construct (?&) was not diagnosed as a syntax error (it referenced the
+ first named subpattern) and a construct such as (?&a) would reference the
+ first named subpattern whose name started with "a" (in other words, the
+ length check was missing). Both these problems are fixed. "Subpattern name
+ expected" is now given for (?&) (a zero-length name), and this patch also
+ makes it give the same error for \k'' (previously it complained that that
+ was a reference to a non-existent subpattern).
+
+6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
+ this is right because (?- can be followed by option settings as well as by
+ digits. I have, however, made the messages clearer.
+
+7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
+ than the number used in the conditional) now cause a compile-time error.
+ This is actually not compatible with Perl, which accepts such patterns, but
+ treats the conditional as always being FALSE (as PCRE used to), but it
+ seems to me that giving a diagnostic is better.
+
+
+Version 7.4 21-Sep-07
+---------------------
+
+1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
+ means that a class such as [\s] counted as "explicit reference to CR or
+ LF". That isn't really right - the whole point of the change was to try to
+ help when there was an actual mention of one of the two characters. So now
+ the change happens only if \r or \n (or a literal CR or LF) character is
+ encountered.
+
+2. The 32-bit options word was also used for 6 internal flags, but the numbers
+ of both had grown to the point where there were only 3 bits left.
+ Fortunately, there was spare space in the data structure, and so I have
+ moved the internal flags into a new 16-bit field to free up more option
+ bits.
+
+3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
+ but did not set the internal JCHANGED flag - either of these is enough to
+ control the way the "get" function works - but the PCRE_INFO_JCHANGED
+ facility is supposed to tell if (?J) was ever used, so now (?J) at the
+ start sets both bits.
+
+4. Added options (at build time, compile time, exec time) to change \R from
+ matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
+
+5. doc/pcresyntax.html was missing from the distribution.
+
+6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
+ compatibility, even though it is no longer used.
+
+7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
+ strtoull to pcrecpp.cc to select the available functions in WIN32 when the
+ windows.h file is present (where different names are used). [This was
+ reversed later after testing - see 16 below.]
+
+8. Changed all #include to #include "config.h". There were also
+ some further cases that I changed to "pcre.h".
+
+9. When pcregrep was used with the --colour option, it missed the line ending
+ sequence off the lines that it output.
+
+10. It was pointed out to me that arrays of string pointers cause lots of
+ relocations when a shared library is dynamically loaded. A technique of
+ using a single long string with a table of offsets can drastically reduce
+ these. I have refactored PCRE in four places to do this. The result is
+ dramatic:
+
+ Originally: 290
+ After changing UCP table: 187
+ After changing error message table: 43
+ After changing table of "verbs" 36
+ After changing table of Posix names 22
+
+ Thanks to the folks working on Gregex for glib for this insight.
+
+11. --disable-stack-for-recursion caused compiling to fail unless -enable-
+ unicode-properties was also set.
+
+12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
+
+13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
+ checked only for CRLF.
+
+14. Added casts to pcretest.c to avoid compiler warnings.
+
+15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
+
+16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
+ and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
+ entirely. This removes changes made in 7 above.
+
+17. The CMake files have been updated, and there is now more information about
+ building with CMake in the NON-UNIX-USE document.
+
+
+Version 7.3 28-Aug-07
+---------------------
+
+ 1. In the rejigging of the build system that eventually resulted in 7.1, the
+ line "#include " was included in pcre_internal.h. The use of angle
+ brackets there is not right, since it causes compilers to look for an
+ installed pcre.h, not the version that is in the source that is being
+ compiled (which of course may be different). I have changed it back to:
+
+ #include "pcre.h"
+
+ I have a vague recollection that the change was concerned with compiling in
+ different directories, but in the new build system, that is taken care of
+ by the VPATH setting the Makefile.
+
+ 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
+ when the subject happened to end in the byte 0x85 (e.g. if the last
+ character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
+ characters but of course it shouldn't be taken as a newline when it is part
+ of another character. The bug was that, for an unlimited repeat of . in
+ not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
+ characters when looking for a newline.
+
+ 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
+
+ 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
+ in debug output.
+
+ 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
+ long printing in the pcrecpp unittest when running under MinGW.
+
+ 6. ESC_K was left out of the EBCDIC table.
+
+ 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
+ parentheses; I made it 1000, which seemed large enough. Unfortunately, the
+ limit also applies to "virtual nesting" when a pattern is recursive, and in
+ this case 1000 isn't so big. I have been able to remove this limit at the
+ expense of backing off one optimization in certain circumstances. Normally,
+ when pcre_exec() would call its internal match() function recursively and
+ immediately return the result unconditionally, it uses a "tail recursion"
+ feature to save stack. However, when a subpattern that can match an empty
+ string has an unlimited repetition quantifier, it no longer makes this
+ optimization. That gives it a stack frame in which to save the data for
+ checking that an empty string has been matched. Previously this was taken
+ from the 1000-entry workspace that had been reserved. So now there is no
+ explicit limit, but more stack is used.
+
+ 8. Applied Daniel's patches to solve problems with the import/export magic
+ syntax that is required for Windows, and which was going wrong for the
+ pcreposix and pcrecpp parts of the library. These were overlooked when this
+ problem was solved for the main library.
+
+ 9. There were some crude static tests to avoid integer overflow when computing
+ the size of patterns that contain repeated groups with explicit upper
+ limits. As the maximum quantifier is 65535, the maximum group length was
+ set at 30,000 so that the product of these two numbers did not overflow a
+ 32-bit integer. However, it turns out that people want to use groups that
+ are longer than 30,000 bytes (though not repeat them that many times).
+ Change 7.0/17 (the refactoring of the way the pattern size is computed) has
+ made it possible to implement the integer overflow checks in a much more
+ dynamic way, which I have now done. The artificial limitation on group
+ length has been removed - we now have only the limit on the total length of
+ the compiled pattern, which depends on the LINK_SIZE setting.
+
+10. Fixed a bug in the documentation for get/copy named substring when
+ duplicate names are permitted. If none of the named substrings are set, the
+ functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
+ empty string.
+
+11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
+ instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
+ because the ] is interpreted as the first data character and the
+ terminating ] is not found. PCRE has been made compatible with Perl in this
+ regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
+ cause memory overwriting.
+
+10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
+ string has been matched (to stop an infinite loop). It was not recognizing
+ a conditional subpattern that could match an empty string if that
+ subpattern was within another subpattern. For example, it looped when
+ trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
+ condition was not nested. This bug has been fixed.
+
+12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
+ past the start of the subject in the presence of bytes with the top bit
+ set, for example "\x8aBCD".
+
+13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
+ (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
+
+14. Optimized (?!) to (*FAIL).
+
+15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
+ This restricts code points to be within the range 0 to 0x10FFFF, excluding
+ the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
+ full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
+ does: it's just the validity check that is more restrictive.
+
+16. Inserted checks for integer overflows during escape sequence (backslash)
+ processing, and also fixed erroneous offset values for syntax errors during
+ backslash processing.
+
+17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
+ for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
+
+18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
+ caused an overrun.
+
+19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
+ something other than just ASCII characters) inside a group that had an
+ unlimited repeat caused a loop at compile time (while checking to see
+ whether the group could match an empty string).
+
+20. Debugging a pattern containing \p or \P could cause a crash. For example,
+ [\P{Any}] did so. (Error in the code for printing property names.)
+
+21. An orphan \E inside a character class could cause a crash.
+
+22. A repeated capturing bracket such as (A)? could cause a wild memory
+ reference during compilation.
+
+23. There are several functions in pcre_compile() that scan along a compiled
+ expression for various reasons (e.g. to see if it's fixed length for look
+ behind). There were bugs in these functions when a repeated \p or \P was
+ present in the pattern. These operators have additional parameters compared
+ with \d, etc, and these were not being taken into account when moving along
+ the compiled data. Specifically:
+
+ (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
+ length.
+
+ (b) An item such as \pL+ within a repeated group could cause crashes or
+ loops.
+
+ (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
+ "reference to non-existent subpattern" error.
+
+ (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
+
+24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
+ characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
+
+25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
+
+26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
+ character were causing crashes (broken optimization).
+
+27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
+ \p or \P) caused a compile-time loop.
+
+28. More problems have arisen in unanchored patterns when CRLF is a valid line
+ break. For example, the unstudied pattern [\r\n]A does not match the string
+ "\r\nA" because change 7.0/46 below moves the current point on by two
+ characters after failing to match at the start. However, the pattern \nA
+ *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
+ the same is true. There doesn't seem any very clean way out of this, but
+ what I have chosen to do makes the common cases work: PCRE now takes note
+ of whether there can be an explicit match for \r or \n anywhere in the
+ pattern, and if so, 7.0/46 no longer applies. As part of this change,
+ there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
+ pattern has explicit CR or LF references.
+
+29. Added (*CR) etc for changing newline setting at start of pattern.
+
+
+Version 7.2 19-Jun-07
+---------------------
+
+ 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
+ which is apparently normally available under Windows.
+
+ 2. Re-jig the pcregrep tests with different newline settings in an attempt
+ to make them independent of the local environment's newline setting.
+
+ 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
+
+ 4. Some of the "internals" tests were previously cut out when the link size
+ was not 2, because the output contained actual offsets. The recent new
+ "Z" feature of pcretest means that these can be cut out, making the tests
+ usable with all link sizes.
+
+ 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
+ stack recursion. This gives a massive performance boost under BSD, but just
+ a small improvement under Linux. However, it saves one field in the frame
+ in all cases.
+
+ 6. Added more features from the forthcoming Perl 5.10:
+
+ (a) (?-n) (where n is a string of digits) is a relative subroutine or
+ recursion call. It refers to the nth most recently opened parentheses.
+
+ (b) (?+n) is also a relative subroutine call; it refers to the nth next
+ to be opened parentheses.
+
+ (c) Conditions that refer to capturing parentheses can be specified
+ relatively, for example, (?(-2)... or (?(+3)...
+
+ (d) \K resets the start of the current match so that everything before
+ is not part of it.
+
+ (e) \k{name} is synonymous with \k and \k'name' (.NET compatible).
+
+ (f) \g{name} is another synonym - part of Perl 5.10's unification of
+ reference syntax.
+
+ (g) (?| introduces a group in which the numbering of parentheses in each
+ alternative starts with the same number.
+
+ (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
+
+ 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
+ PCRE_INFO_JCHANGED.
+
+ 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
+ terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
+ for detecting groups that can match an empty string.
+
+ 9. A pattern with a very large number of alternatives (more than several
+ hundred) was running out of internal workspace during the pre-compile
+ phase, where pcre_compile() figures out how much memory will be needed. A
+ bit of new cunning has reduced the workspace needed for groups with
+ alternatives. The 1000-alternative test pattern now uses 12 bytes of
+ workspace instead of running out of the 4096 that are available.
+
+10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
+
+11. Applied patch from Google to remove an optimization that didn't quite work.
+ The report of the bug said:
+
+ pcrecpp::RE("a*").FullMatch("aaa") matches, while
+ pcrecpp::RE("a*?").FullMatch("aaa") does not, and
+ pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
+
+12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
+ it matched the wrong number of bytes.
+
+
+Version 7.1 24-Apr-07
+---------------------
+
+ 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
+ that is more "standard", making use of automake and other Autotools. There
+ is some re-arrangement of the files and adjustment of comments consequent
+ on this.
+
+ 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
+ for recursive directory scanning broke on some systems because the files
+ are not scanned in any specific order and on different systems the order
+ was different. A call to "sort" has been inserted into RunGrepTest for the
+ approprate test as a short-term fix. In the longer term there may be an
+ alternative.
+
+ 3. I had an email from Eric Raymond about problems translating some of PCRE's
+ man pages to HTML (despite the fact that I distribute HTML pages, some
+ people do their own conversions for various reasons). The problems
+ concerned the use of low-level troff macros .br and .in. I have therefore
+ removed all such uses from the man pages (some were redundant, some could
+ be replaced by .nf/.fi pairs). The 132html script that I use to generate
+ HTML has been updated to handle .nf/.fi and to complain if it encounters
+ .br or .in.
+
+ 4. Updated comments in configure.ac that get placed in config.h.in and also
+ arranged for config.h to be included in the distribution, with the name
+ config.h.generic, for the benefit of those who have to compile without
+ Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
+
+ 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
+ Weber: (1) pcre_internal.h was missing some function renames; (2) updated
+ makevp.bat for the current PCRE, using the additional files
+ makevp_c.txt, makevp_l.txt, and pcregexp.pas.
+
+ 6. A Windows user reported a minor discrepancy with test 2, which turned out
+ to be caused by a trailing space on an input line that had got lost in his
+ copy. The trailing space was an accident, so I've just removed it.
+
+ 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
+ that is needed.
+
+ 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
+ as "const" (a) because they are and (b) because it helps the PHP
+ maintainers who have recently made a script to detect big data structures
+ in the php code that should be moved to the .rodata section. I remembered
+ to update Builducptable as well, so it won't revert if ucptable.h is ever
+ re-created.
+
+ 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
+ pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
+ order to be able to cut out the UTF-8 tables in the latter when UTF-8
+ support is not required. This saves 1.5-2K of code, which is important in
+ some applications.
+
+ Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
+ so as not to refer to the tables, even though these functions will never be
+ called when UTF-8 support is disabled. Otherwise there are problems with a
+ shared library.
+
+10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
+
+ (a) It was defining its arguments as char * instead of void *.
+
+ (b) It was assuming that all moves were upwards in memory; this was true
+ a long time ago when I wrote it, but is no longer the case.
+
+ The emulated memove() is provided for those environments that have neither
+ memmove() nor bcopy(). I didn't think anyone used it these days, but that
+ is clearly not the case, as these two bugs were recently reported.
+
+11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
+ and Detrail to create the HTML documentation, the .txt form of the man
+ pages, and it removes trailing spaces from listed files. It also creates
+ pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
+ case, it wraps all the #defines with #ifndefs. This script should be run
+ before "make dist".
+
+12. Fixed two fairly obscure bugs concerned with quantified caseless matching
+ with Unicode property support.
+
+ (a) For a maximizing quantifier, if the two different cases of the
+ character were of different lengths in their UTF-8 codings (there are
+ some cases like this - I found 11), and the matching function had to
+ back up over a mixture of the two cases, it incorrectly assumed they
+ were both the same length.
+
+ (b) When PCRE was configured to use the heap rather than the stack for
+ recursion during matching, it was not correctly preserving the data for
+ the other case of a UTF-8 character when checking ahead for a match
+ while processing a minimizing repeat. If the check also involved
+ matching a wide character, but failed, corruption could cause an
+ erroneous result when trying to check for a repeat of the original
+ character.
+
+13. Some tidying changes to the testing mechanism:
+
+ (a) The RunTest script now detects the internal link size and whether there
+ is UTF-8 and UCP support by running ./pcretest -C instead of relying on
+ values substituted by "configure". (The RunGrepTest script already did
+ this for UTF-8.) The configure.ac script no longer substitutes the
+ relevant variables.
+
+ (b) The debugging options /B and /D in pcretest show the compiled bytecode
+ with length and offset values. This means that the output is different
+ for different internal link sizes. Test 2 is skipped for link sizes
+ other than 2 because of this, bypassing the problem. Unfortunately,
+ there was also a test in test 3 (the locale tests) that used /B and
+ failed for link sizes other than 2. Rather than cut the whole test out,
+ I have added a new /Z option to pcretest that replaces the length and
+ offset values with spaces. This is now used to make test 3 independent
+ of link size. (Test 2 will be tidied up later.)
+
+14. If erroroffset was passed as NULL to pcre_compile, it provoked a
+ segmentation fault instead of returning the appropriate error message.
+
+15. In multiline mode when the newline sequence was set to "any", the pattern
+ ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
+ This doesn't seem right; it now treats the CRLF combination as the line
+ ending, and so does not match in that case. It's only a pattern such as ^$
+ that would hit this one: something like ^ABC$ would have failed after \r
+ and then tried again after \r\n.
+
+16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
+ in an attempt to make files that differ only in their line terminators
+ compare equal. This works on Linux.
+
+17. Under certain error circumstances pcregrep might try to free random memory
+ as it exited. This is now fixed, thanks to valgrind.
+
+19. In pcretest, if the pattern /(?m)^$/g was matched against the string
+ "abc\r\n\r\n", it found an unwanted second match after the second \r. This
+ was because its rules for how to advance for /g after matching an empty
+ string at the end of a line did not allow for this case. They now check for
+ it specially.
+
+20. pcretest is supposed to handle patterns and data of any length, by
+ extending its buffers when necessary. It was getting this wrong when the
+ buffer for a data line had to be extended.
+
+21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
+ CRLF as a newline sequence.
+
+22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
+ out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
+ I have nevertheless tidied it up.
+
+23. Added some casts to kill warnings from HP-UX ia64 compiler.
+
+24. Added a man page for pcre-config.
+
+
+Version 7.0 19-Dec-06
+---------------------
+
+ 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
+ moving to gcc 4.1.1.
+
+ 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
+ sys/time.h, which is documented as needed for this function. It doesn't
+ seem to matter on Linux, but it showed up on some releases of OS X.
+
+ 3. It seems that there are systems where bytes whose values are greater than
+ 127 match isprint() in the "C" locale. The "C" locale should be the
+ default when a C program starts up. In most systems, only ASCII printing
+ characters match isprint(). This difference caused the output from pcretest
+ to vary, making some of the tests fail. I have changed pcretest so that:
+
+ (a) When it is outputting text in the compiled version of a pattern, bytes
+ other than 32-126 are always shown as hex escapes.
+
+ (b) When it is outputting text that is a matched part of a subject string,
+ it does the same, unless a different locale has been set for the match
+ (using the /L modifier). In this case, it uses isprint() to decide.
+
+ 4. Fixed a major bug that caused incorrect computation of the amount of memory
+ required for a compiled pattern when options that changed within the
+ pattern affected the logic of the preliminary scan that determines the
+ length. The relevant options are -x, and -i in UTF-8 mode. The result was
+ that the computed length was too small. The symptoms of this bug were
+ either the PCRE error "internal error: code overflow" from pcre_compile(),
+ or a glibc crash with a message such as "pcretest: free(): invalid next
+ size (fast)". Examples of patterns that provoked this bug (shown in
+ pcretest format) are:
+
+ /(?-x: )/x
+ /(?x)(?-x: \s*#\s*)/
+ /((?i)[\x{c0}])/8
+ /(?i:[\x{c0}])/8
+
+ HOWEVER: Change 17 below makes this fix obsolete as the memory computation
+ is now done differently.
+
+ 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
+ wrapper classes; (b) implement a new function in the C++ scanner that is
+ more efficient than the old way of doing things because it avoids levels of
+ recursion in the regex matching; (c) add a paragraph to the documentation
+ for the FullMatch() function.
+
+ 6. The escape sequence \n was being treated as whatever was defined as
+ "newline". Not only was this contrary to the documentation, which states
+ that \n is character 10 (hex 0A), but it also went horribly wrong when
+ "newline" was defined as CRLF. This has been fixed.
+
+ 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
+ was being set to -1 for the "end of line" case (supposedly a value that no
+ character can have). Though this value is never used (the check for end of
+ line is "zero bytes in current character"), it caused compiler complaints.
+ I've changed it to 0xffffffff.
+
+ 8. In pcre_version.c, the version string was being built by a sequence of
+ C macros that, in the event of PCRE_PRERELEASE being defined as an empty
+ string (as it is for production releases) called a macro with an empty
+ argument. The C standard says the result of this is undefined. The gcc
+ compiler treats it as an empty string (which was what was wanted) but it is
+ reported that Visual C gives an error. The source has been hacked around to
+ avoid this problem.
+
+ 9. On the advice of a Windows user, included and in Windows
+ builds of pcretest, and changed the call to _setmode() to use _O_BINARY
+ instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
+ of them did).
+
+10. Originally, pcretest opened its input and output without "b"; then I was
+ told that "b" was needed in some environments, so it was added for release
+ 5.0 to both the input and output. (It makes no difference on Unix-like
+ systems.) Later I was told that it is wrong for the input on Windows. I've
+ now abstracted the modes into two macros, to make it easier to fiddle with
+ them, and removed "b" from the input mode under Windows.
+
+11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
+
+12. Added -help and --help to pcretest as an official way of being reminded
+ of the options.
+
+13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
+ and pcrecpp.cc because they annoy compilers at high warning levels.
+
+14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
+
+15. Fixed an occurrence of == in configure.ac that should have been = (shell
+ scripts are not C programs :-) and which was not noticed because it works
+ on Linux.
+
+16. pcretest is supposed to handle any length of pattern and data line (as one
+ line or as a continued sequence of lines) by extending its input buffer if
+ necessary. This feature was broken for very long pattern lines, leading to
+ a string of junk being passed to pcre_compile() if the pattern was longer
+ than about 50K.
+
+17. I have done a major re-factoring of the way pcre_compile() computes the
+ amount of memory needed for a compiled pattern. Previously, there was code
+ that made a preliminary scan of the pattern in order to do this. That was
+ OK when PCRE was new, but as the facilities have expanded, it has become
+ harder and harder to keep it in step with the real compile phase, and there
+ have been a number of bugs (see for example, 4 above). I have now found a
+ cunning way of running the real compile function in a "fake" mode that
+ enables it to compute how much memory it would need, while actually only
+ ever using a few hundred bytes of working memory and without too many
+ tests of the mode. This should make future maintenance and development
+ easier. A side effect of this work is that the limit of 200 on the nesting
+ depth of parentheses has been removed (though this was never a serious
+ limitation, I suspect). However, there is a downside: pcre_compile() now
+ runs more slowly than before (30% or more, depending on the pattern). I
+ hope this isn't a big issue. There is no effect on runtime performance.
+
+18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
+ newline (only possible for the last line of a file) and it was a
+ pattern that set a locale (followed by /Lsomething), pcretest crashed.
+
+19. Added additional timing features to pcretest. (1) The -tm option now times
+ matching only, not compiling. (2) Both -t and -tm can be followed, as a
+ separate command line item, by a number that specifies the number of
+ repeats to use when timing. The default is 50000; this gives better
+ precision, but takes uncomfortably long for very large patterns.
+
+20. Extended pcre_study() to be more clever in cases where a branch of a
+ subpattern has no definite first character. For example, (a*|b*)[cd] would
+ previously give no result from pcre_study(). Now it recognizes that the
+ first character must be a, b, c, or d.
+
+21. There was an incorrect error "recursive call could loop indefinitely" if
+ a subpattern (or the entire pattern) that was being tested for matching an
+ empty string contained only one non-empty item after a nested subpattern.
+ For example, the pattern (?>\x{100}*)\d(?R) provoked this error
+ incorrectly, because the \d was being skipped in the check.
+
+22. The pcretest program now has a new pattern option /B and a command line
+ option -b, which is equivalent to adding /B to every pattern. This causes
+ it to show the compiled bytecode, without the additional information that
+ -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
+ is the same as /B/I).
+
+23. A new optimization is now able automatically to treat some sequences such
+ as a*b as a*+b. More specifically, if something simple (such as a character
+ or a simple class like \d) has an unlimited quantifier, and is followed by
+ something that cannot possibly match the quantified thing, the quantifier
+ is automatically "possessified".
+
+24. A recursive reference to a subpattern whose number was greater than 39
+ went wrong under certain circumstances in UTF-8 mode. This bug could also
+ have affected the operation of pcre_study().
+
+25. Realized that a little bit of performance could be had by replacing
+ (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
+
+26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
+
+27. Possessive quantifiers such as a++ were previously implemented by turning
+ them into atomic groups such as ($>a+). Now they have their own opcodes,
+ which improves performance. This includes the automatically created ones
+ from 23 above.
+
+28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
+ lookahead was broken if it was not anchored. PCRE was mistakenly expecting
+ the first matched character to be a colon. This applied both to named and
+ numbered groups.
+
+29. The ucpinternal.h header file was missing its idempotency #ifdef.
+
+30. I was sent a "project" file called libpcre.a.dev which I understand makes
+ building PCRE on Windows easier, so I have included it in the distribution.
+
+31. There is now a check in pcretest against a ridiculously large number being
+ returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
+ loop, the loop is abandoned.
+
+32. Forward references to subpatterns in conditions such as (?(2)...) where
+ subpattern 2 is defined later cause pcre_compile() to search forwards in
+ the pattern for the relevant set of parentheses. This search went wrong
+ when there were unescaped parentheses in a character class, parentheses
+ escaped with \Q...\E, or parentheses in a #-comment in /x mode.
+
+33. "Subroutine" calls and backreferences were previously restricted to
+ referencing subpatterns earlier in the regex. This restriction has now
+ been removed.
+
+34. Added a number of extra features that are going to be in Perl 5.10. On the
+ whole, these are just syntactic alternatives for features that PCRE had
+ previously implemented using the Python syntax or my own invention. The
+ other formats are all retained for compatibility.
+
+ (a) Named groups can now be defined as (?...) or (?'name'...) as well
+ as (?P...). The new forms, as well as being in Perl 5.10, are
+ also .NET compatible.
+
+ (b) A recursion or subroutine call to a named group can now be defined as
+ (?&name) as well as (?P>name).
+
+ (c) A backreference to a named group can now be defined as \k or
+ \k'name' as well as (?P=name). The new forms, as well as being in Perl
+ 5.10, are also .NET compatible.
+
+ (d) A conditional reference to a named group can now use the syntax
+ (?() or (?('name') as well as (?(name).
+
+ (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
+ groups (named and numbered) that are never evaluated inline, but can be
+ called as "subroutines" from elsewhere. In effect, the DEFINE condition
+ is always false. There may be only one alternative in such a group.
+
+ (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
+ as the simple (?(R). The condition is true only if the most recent
+ recursion is that of the given number or name. It does not search out
+ through the entire recursion stack.
+
+ (g) The escape \gN or \g{N} has been added, where N is a positive or
+ negative number, specifying an absolute or relative reference.
+
+35. Tidied to get rid of some further signed/unsigned compiler warnings and
+ some "unreachable code" warnings.
+
+36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
+ things, this adds five new scripts.
+
+37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
+ There were also incompatibilities regarding the handling of \Q..\E inside
+ character classes, for example with patterns like [\Qa\E-\Qz\E] where the
+ hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
+
+38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
+ matches an empty string, and forcibly breaks the loop. There were bugs in
+ this code in non-simple cases. For a pattern such as ^(a()*)* matched
+ against aaaa the result was just "a" rather than "aaaa", for example. Two
+ separate and independent bugs (that affected different cases) have been
+ fixed.
+
+39. Refactored the code to abolish the use of different opcodes for small
+ capturing bracket numbers. This is a tidy that I avoided doing when I
+ removed the limit on the number of capturing brackets for 3.5 back in 2001.
+ The new approach is not only tidier, it makes it possible to reduce the
+ memory needed to fix the previous bug (38).
+
+40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
+ sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
+ processing dot, circumflex, or dollar metacharacters, or #-comments in /x
+ mode.
+
+41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
+ report.
+
+42. Applied patch, originally from Ari Pollak, modified by Google, to allow
+ copy construction and assignment in the C++ wrapper.
+
+43. Updated pcregrep to support "--newline=any". In the process, I fixed a
+ couple of bugs that could have given wrong results in the "--newline=crlf"
+ case.
+
+44. Added a number of casts and did some reorganization of signed/unsigned int
+ variables following suggestions from Dair Grant. Also renamed the variable
+ "this" as "item" because it is a C++ keyword.
+
+45. Arranged for dftables to add
+
+ #include "pcre_internal.h"
+
+ to pcre_chartables.c because without it, gcc 4.x may remove the array
+ definition from the final binary if PCRE is built into a static library and
+ dead code stripping is activated.
+
+46. For an unanchored pattern, if a match attempt fails at the start of a
+ newline sequence, and the newline setting is CRLF or ANY, and the next two
+ characters are CRLF, advance by two characters instead of one.
+
+
+Version 6.7 04-Jul-06
+---------------------
+
+ 1. In order to handle tests when input lines are enormously long, pcretest has
+ been re-factored so that it automatically extends its buffers when
+ necessary. The code is crude, but this _is_ just a test program. The
+ default size has been increased from 32K to 50K.
+
+ 2. The code in pcre_study() was using the value of the re argument before
+ testing it for NULL. (Of course, in any sensible call of the function, it
+ won't be NULL.)
+
+ 3. The memmove() emulation function in pcre_internal.h, which is used on
+ systems that lack both memmove() and bcopy() - that is, hardly ever -
+ was missing a "static" storage class specifier.
+
+ 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
+ containing an extended class (one that cannot be represented by a bitmap
+ because it contains high-valued characters or Unicode property items, e.g.
+ [\pZ]). Almost always one would set UTF-8 mode when processing such a
+ pattern, but PCRE should not loop if you do not (it no longer does).
+ [Detail: two cases were found: (a) a repeated subpattern containing an
+ extended class; (b) a recursive reference to a subpattern that followed a
+ previous extended class. It wasn't skipping over the extended class
+ correctly when UTF-8 mode was not set.]
+
+ 5. A negated single-character class was not being recognized as fixed-length
+ in lookbehind assertions such as (?<=[^f]), leading to an incorrect
+ compile error "lookbehind assertion is not fixed length".
+
+ 6. The RunPerlTest auxiliary script was showing an unexpected difference
+ between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
+ write a Perl script that can interpret lines of an input file either as
+ byte characters or as UTF-8, which is what "perltest" was being required to
+ do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
+ can't do is switch easily at run time between having the "use utf8;" pragma
+ or not. In the end, I fudged it by using the RunPerlTest script to insert
+ "use utf8;" explicitly for the UTF-8 tests.
+
+ 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
+ the end of the subject string, contrary to the documentation and to what
+ Perl does. This was true of both matching functions. Now it matches only at
+ the start of the subject and immediately after *internal* newlines.
+
+ 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
+ a pointer to an int instead of a pointer to an unsigned long int. This
+ caused problems on 64-bit systems.
+
+ 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
+ instance of the 'standard' template library not being so standard".
+
+10. There was no check on the number of named subpatterns nor the maximum
+ length of a subpattern name. The product of these values is used to compute
+ the size of the memory block for a compiled pattern. By supplying a very
+ long subpattern name and a large number of named subpatterns, the size
+ computation could be caused to overflow. This is now prevented by limiting
+ the length of names to 32 characters, and the number of named subpatterns
+ to 10,000.
+
+11. Subpatterns that are repeated with specific counts have to be replicated in
+ the compiled pattern. The size of memory for this was computed from the
+ length of the subpattern and the repeat count. The latter is limited to
+ 65535, but there was no limit on the former, meaning that integer overflow
+ could in principle occur. The compiled length of a repeated subpattern is
+ now limited to 30,000 bytes in order to prevent this.
+
+12. Added the optional facility to have named substrings with the same name.
+
+13. Added the ability to use a named substring as a condition, using the
+ Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
+ are numbers (not recommended). Forward references are permitted.
+
+14. Added forward references in named backreferences (if you see what I mean).
+
+15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
+ pattern could run off the end of the subject. For example, the pattern
+ "(?s)(.{1,5})"8 did this with the subject "ab".
+
+16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
+ PCRE_CASELESS was set when matching characters that were quantified with ?
+ or *.
+
+17. A character class other than a single negated character that had a minimum
+ but no maximum quantifier - for example [ab]{6,} - was not handled
+ correctly by pce_dfa_exec(). It would match only one character.
+
+18. A valid (though odd) pattern that looked like a POSIX character
+ class but used an invalid character after [ (for example [[,abc,]]) caused
+ pcre_compile() to give the error "Failed: internal error: code overflow" or
+ in some cases to crash with a glibc free() error. This could even happen if
+ the pattern terminated after [[ but there just happened to be a sequence of
+ letters, a binary zero, and a closing ] in the memory that followed.
+
+19. Perl's treatment of octal escapes in the range \400 to \777 has changed
+ over the years. Originally (before any Unicode support), just the bottom 8
+ bits were taken. Thus, for example, \500 really meant \100. Nowadays the
+ output from "man perlunicode" includes this:
+
+ The regular expression compiler produces polymorphic opcodes. That
+ is, the pattern adapts to the data and automatically switches to
+ the Unicode character scheme when presented with Unicode data--or
+ instead uses a traditional byte scheme when presented with byte
+ data.
+
+ Sadly, a wide octal escape does not cause a switch, and in a string with
+ no other multibyte characters, these octal escapes are treated as before.
+ Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
+ /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
+ Unicode string.
+
+ I have not perpetrated such confusion in PCRE. Up till now, it took just
+ the bottom 8 bits, as in old Perl. I have now made octal escapes with
+ values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
+ translate to the appropriate multibyte character.
+
+29. Applied some refactoring to reduce the number of warnings from Microsoft
+ and Borland compilers. This has included removing the fudge introduced
+ seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
+ a warning about an unused variable.
+
+21. PCRE has not included VT (character 0x0b) in the set of whitespace
+ characters since release 4.0, because Perl (from release 5.004) does not.
+ [Or at least, is documented not to: some releases seem to be in conflict
+ with the documentation.] However, when a pattern was studied with
+ pcre_study() and all its branches started with \s, PCRE still included VT
+ as a possible starting character. Of course, this did no harm; it just
+ caused an unnecessary match attempt.
+
+22. Removed a now-redundant internal flag bit that recorded the fact that case
+ dependency changed within the pattern. This was once needed for "required
+ byte" processing, but is no longer used. This recovers a now-scarce options
+ bit. Also moved the least significant internal flag bit to the most-
+ significant bit of the word, which was not previously used (hangover from
+ the days when it was an int rather than a uint) to free up another bit for
+ the future.
+
+23. Added support for CRLF line endings as well as CR and LF. As well as the
+ default being selectable at build time, it can now be changed at runtime
+ via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
+ specify that it is scanning data with non-default line endings.
+
+24. Changed the definition of CXXLINK to make it agree with the definition of
+ LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
+
+25. Applied Ian Taylor's patches to avoid using another stack frame for tail
+ recursions. This makes a big different to stack usage for some patterns.
+
+26. If a subpattern containing a named recursion or subroutine reference such
+ as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
+ the space required for the compiled pattern went wrong and gave too small a
+ value. Depending on the environment, this could lead to "Failed: internal
+ error: code overflow at offset 49" or "glibc detected double free or
+ corruption" errors.
+
+27. Applied patches from Google (a) to support the new newline modes and (b) to
+ advance over multibyte UTF-8 characters in GlobalReplace.
+
+28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
+ difference for some implementation of PCRE in some Windows version.
+
+29. Added some extra testing facilities to pcretest:
+
+ \q in a data line sets the "match limit" value
+ \Q in a data line sets the "match recursion limt" value
+ -S sets the stack size, where is in megabytes
+
+ The -S option isn't available for Windows.
+
+
+Version 6.6 06-Feb-06
+---------------------
+
+ 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
+ in pcreposix.h. I have copied the definition from pcre.h.
+
+ 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
+ because pcre.h is no longer a built file.
+
+ 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
+ not normally included in the compiled code.
+
+
+Version 6.5 01-Feb-06
+---------------------
+
+ 1. When using the partial match feature with pcre_dfa_exec(), it was not
+ anchoring the second and subsequent partial matches at the new starting
+ point. This could lead to incorrect results. For example, with the pattern
+ /1234/, partially matching against "123" and then "a4" gave a match.
+
+ 2. Changes to pcregrep:
+
+ (a) All non-match returns from pcre_exec() were being treated as failures
+ to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
+ error message is output. Some extra information is given for the
+ PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
+ probably the only errors that are likely to be caused by users (by
+ specifying a regex that has nested indefinite repeats, for instance).
+ If there are more than 20 of these errors, pcregrep is abandoned.
+
+ (b) A binary zero was treated as data while matching, but terminated the
+ output line if it was written out. This has been fixed: binary zeroes
+ are now no different to any other data bytes.
+
+ (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
+ used to set a locale for matching. The --locale=xxxx long option has
+ been added (no short equivalent) to specify a locale explicitly on the
+ pcregrep command, overriding the environment variables.
+
+ (d) When -B was used with -n, some line numbers in the output were one less
+ than they should have been.
+
+ (e) Added the -o (--only-matching) option.
+
+ (f) If -A or -C was used with -c (count only), some lines of context were
+ accidentally printed for the final match.
+
+ (g) Added the -H (--with-filename) option.
+
+ (h) The combination of options -rh failed to suppress file names for files
+ that were found from directory arguments.
+
+ (i) Added the -D (--devices) and -d (--directories) options.
+
+ (j) Added the -F (--fixed-strings) option.
+
+ (k) Allow "-" to be used as a file name for -f as well as for a data file.
+
+ (l) Added the --colo(u)r option.
+
+ (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
+ is not present by default.
+
+ 3. A nasty bug was discovered in the handling of recursive patterns, that is,
+ items such as (?R) or (?1), when the recursion could match a number of
+ alternatives. If it matched one of the alternatives, but subsequently,
+ outside the recursion, there was a failure, the code tried to back up into
+ the recursion. However, because of the way PCRE is implemented, this is not
+ possible, and the result was an incorrect result from the match.
+
+ In order to prevent this happening, the specification of recursion has
+ been changed so that all such subpatterns are automatically treated as
+ atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
+
+ 4. I had overlooked the fact that, in some locales, there are characters for
+ which isalpha() is true but neither isupper() nor islower() are true. In
+ the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
+ and ordfeminine) are like this. This affected the treatment of \w and \W
+ when they appeared in character classes, but not when they appeared outside
+ a character class. The bit map for "word" characters is now created
+ separately from the results of isalnum() instead of just taking it from the
+ upper, lower, and digit maps. (Plus the underscore character, of course.)
+
+ 5. The above bug also affected the handling of POSIX character classes such as
+ [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
+ permanent tables. Instead, the bit maps for such a class were previously
+ created as the appropriate unions of the upper, lower, and digit bitmaps.
+ Now they are created by subtraction from the [[:word:]] class, which has
+ its own bitmap.
+
+ 6. The [[:blank:]] character class matches horizontal, but not vertical space.
+ It is created by subtracting the vertical space characters (\x09, \x0a,
+ \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
+ subtraction was done in the overall bitmap for a character class, meaning
+ that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
+ be recognized. This bug has been fixed.
+
+ 7. Patches from the folks at Google:
+
+ (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
+ real life, but is still worth protecting against".
+
+ (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
+ regular expressions".
+
+ (c) pcre_scanner.cc: avoid use of std::count() because not all systems
+ have it.
+
+ (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
+ "configure" and the latter not, in order to fix a problem somebody had
+ with compiling the Arg class on HP-UX.
+
+ (e) Improve the error-handling of the C++ wrapper a little bit.
+
+ (f) New tests for checking recursion limiting.
+
+ 8. The pcre_memmove() function, which is used only if the environment does not
+ have a standard memmove() function (and is therefore rarely compiled),
+ contained two bugs: (a) use of int instead of size_t, and (b) it was not
+ returning a result (though PCRE never actually uses the result).
+
+ 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
+ large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
+ returned instead of calling malloc() with an overflowing number that would
+ most likely cause subsequent chaos.
+
+10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
+
+11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
+ with this option is matched, the nmatch and pmatch options of regexec() are
+ ignored.
+
+12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
+ provided in case anyone wants to the the POSIX interface with UTF-8
+ strings.
+
+13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
+ C++ linking (needed for some HP-UX environments).
+
+14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
+ (unused parameter) and in the pcre_printint() function (omitted "default"
+ switch label when the default is to do nothing).
+
+15. Added some code to make it possible, when PCRE is compiled as a C++
+ library, to replace subject pointers for pcre_exec() with a smart pointer
+ class, thus making it possible to process discontinuous strings.
+
+16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
+ much the same function. They were added by different people who were trying
+ to make PCRE easy to compile on non-Unix systems. It has been suggested
+ that PCRE_EXPORT be abolished now that there is more automatic apparatus
+ for compiling on Windows systems. I have therefore replaced it with
+ PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
+ defaults to "extern" for C or "extern C" for C++, which works fine on
+ Unix-like systems. It is now possible to override the value of PCRE_DATA_
+ SCOPE with something explicit in config.h. In addition:
+
+ (a) pcreposix.h still had just "extern" instead of either of these macros;
+ I have replaced it with PCRE_DATA_SCOPE.
+
+ (b) Functions such as _pcre_xclass(), which are internal to the library,
+ but external in the C sense, all had PCRE_EXPORT in their definitions.
+ This is apparently wrong for the Windows case, so I have removed it.
+ (It makes no difference on Unix-like systems.)
+
+17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
+ of recursive calls to match(). This is different to MATCH_LIMIT because
+ that limits the total number of calls to match(), not all of which increase
+ the depth of recursion. Limiting the recursion depth limits the amount of
+ stack (or heap if NO_RECURSE is set) that is used. The default can be set
+ when PCRE is compiled, and changed at run time. A patch from Google adds
+ this functionality to the C++ interface.
+
+18. Changes to the handling of Unicode character properties:
+
+ (a) Updated the table to Unicode 4.1.0.
+
+ (b) Recognize characters that are not in the table as "Cn" (undefined).
+
+ (c) I revised the way the table is implemented to a much improved format
+ which includes recognition of ranges. It now supports the ranges that
+ are defined in UnicodeData.txt, and it also amalgamates other
+ characters into ranges. This has reduced the number of entries in the
+ table from around 16,000 to around 3,000, thus reducing its size
+ considerably. I realized I did not need to use a tree structure after
+ all - a binary chop search is just as efficient. Having reduced the
+ number of entries, I extended their size from 6 bytes to 8 bytes to
+ allow for more data.
+
+ (d) Added support for Unicode script names via properties such as \p{Han}.
+
+19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
+ matching that character.
+
+20. When matching a repeated Unicode property with a minimum greater than zero,
+ (for example \pL{2,}), PCRE could look past the end of the subject if it
+ reached it while seeking the minimum number of characters. This could
+ happen only if some of the characters were more than one byte long, because
+ there is a check for at least the minimum number of bytes.
+
+21. Refactored the implementation of \p and \P so as to be more general, to
+ allow for more different types of property in future. This has changed the
+ compiled form incompatibly. Anybody with saved compiled patterns that use
+ \p or \P will have to recompile them.
+
+22. Added "Any" and "L&" to the supported property types.
+
+23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
+ but give a compile time error if the value is greater than 0xff.
+
+24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
+ accidentally not being installed or uninstalled.
+
+25. The pcre.h file was built from pcre.h.in, but the only changes that were
+ made were to insert the current release number. This seemed silly, because
+ it made things harder for people building PCRE on systems that don't run
+ "configure". I have turned pcre.h into a distributed file, no longer built
+ by "configure", with the version identification directly included. There is
+ no longer a pcre.h.in file.
+
+ However, this change necessitated a change to the pcre-config script as
+ well. It is built from pcre-config.in, and one of the substitutions was the
+ release number. I have updated configure.ac so that ./configure now finds
+ the release number by grepping pcre.h.
+
+26. Added the ability to run the tests under valgrind.
+
+
+Version 6.4 05-Sep-05
+---------------------
+
+ 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
+ "--" to be printed when multiple files were scanned, even when none of the
+ -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
+ consider it to be a bug, and have restored the previous behaviour.
+
+ 2. A couple of code tidies to get rid of compiler warnings.
+
+ 3. The pcretest program used to cheat by referring to symbols in the library
+ whose names begin with _pcre_. These are internal symbols that are not
+ really supposed to be visible externally, and in some environments it is
+ possible to suppress them. The cheating is now confined to including
+ certain files from the library's source, which is a bit cleaner.
+
+ 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
+ file's purpose clearer.
+
+ 5. Reorganized pcre_ucp_findchar().
+
+
+Version 6.3 15-Aug-05
+---------------------
+
+ 1. The file libpcre.pc.in did not have general read permission in the tarball.
+
+ 2. There were some problems when building without C++ support:
+
+ (a) If C++ support was not built, "make install" and "make test" still
+ tried to test it.
+
+ (b) There were problems when the value of CXX was explicitly set. Some
+ changes have been made to try to fix these, and ...
+
+ (c) --disable-cpp can now be used to explicitly disable C++ support.
+
+ (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
+ backslash in a target when C++ was disabled. This confuses some
+ versions of "make", apparently. Using an intermediate variable solves
+ this. (Same for CPP_LOBJ.)
+
+ 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
+ (non-Windows) now includes $(CFLAGS) because these flags are sometimes
+ necessary on certain architectures.
+
+ 4. Added a setting of -export-symbols-regex to the link command to remove
+ those symbols that are exported in the C sense, but actually are local
+ within the library, and not documented. Their names all begin with
+ "_pcre_". This is not a perfect job, because (a) we have to except some
+ symbols that pcretest ("illegally") uses, and (b) the facility isn't always
+ available (and never for static libraries). I have made a note to try to
+ find a way round (a) in the future.
+
+
+Version 6.2 01-Aug-05
+---------------------
+
+ 1. There was no test for integer overflow of quantifier values. A construction
+ such as {1111111111111111} would give undefined results. What is worse, if
+ a minimum quantifier for a parenthesized subpattern overflowed and became
+ negative, the calculation of the memory size went wrong. This could have
+ led to memory overwriting.
+
+ 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
+
+ 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
+ operating environments where this matters.
+
+ 4. Applied Giuseppe Maxia's patch to add additional features for controlling
+ PCRE options from within the C++ wrapper.
+
+ 5. Named capturing subpatterns were not being correctly counted when a pattern
+ was compiled. This caused two problems: (a) If there were more than 100
+ such subpatterns, the calculation of the memory needed for the whole
+ compiled pattern went wrong, leading to an overflow error. (b) Numerical
+ back references of the form \12, where the number was greater than 9, were
+ not recognized as back references, even though there were sufficient
+ previous subpatterns.
+
+ 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
+ versions of gcc, e.g. 2.95.4.
+
+
+Version 6.1 21-Jun-05
+---------------------
+
+ 1. There was one reference to the variable "posix" in pcretest.c that was not
+ surrounded by "#if !defined NOPOSIX".
+
+ 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
+ the cross-check on the old pcre_info() function, for the benefit of the
+ cut-down version of PCRE that is currently imported into Exim.
+
+ 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
+ allocation error. I've done the easy fix, which wastes 2 bytes for sensible
+ patterns that start (?i) but I don't think that matters. The use of (?i) is
+ just an example; this all applies to the other options as well.
+
+ 4. Since libtool seems to echo the compile commands it is issuing, the output
+ from "make" can be reduced a bit by putting "@" in front of each libtool
+ compile command.
+
+ 5. Patch from the folks at Google for configure.in to be a bit more thorough
+ in checking for a suitable C++ installation before trying to compile the
+ C++ stuff. This should fix a reported problem when a compiler was present,
+ but no suitable headers.
+
+ 6. The man pages all had just "PCRE" as their title. I have changed them to
+ be the relevant file name. I have also arranged that these names are
+ retained in the file doc/pcre.txt, which is a concatenation in text format
+ of all the man pages except the little individual ones for each function.
+
+ 7. The NON-UNIX-USE file had not been updated for the different set of source
+ files that come with release 6. I also added a few comments about the C++
+ wrapper.
+
+
+Version 6.0 07-Jun-05
+---------------------
+
+ 1. Some minor internal re-organization to help with my DFA experiments.
+
+ 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
+ didn't matter for the library itself when fully configured, but did matter
+ when compiling without UCP support, or within Exim, where the ucp files are
+ not imported.
+
+ 3. Refactoring of the library code to split up the various functions into
+ different source modules. The addition of the new DFA matching code (see
+ below) to a single monolithic source would have made it really too
+ unwieldy, quite apart from causing all the code to be include in a
+ statically linked application, when only some functions are used. This is
+ relevant even without the DFA addition now that patterns can be compiled in
+ one application and matched in another.
+
+ The downside of splitting up is that there have to be some external
+ functions and data tables that are used internally in different modules of
+ the library but which are not part of the API. These have all had their
+ names changed to start with "_pcre_" so that they are unlikely to clash
+ with other external names.
+
+ 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
+ a different (DFA) algorithm. Although it is slower than the original
+ function, it does have some advantages for certain types of matching
+ problem.
+
+ 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
+ including restarting after a partial match.
+
+ 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
+ defined when compiling for Windows was sent to me. I have put it into the
+ code, though I have no means of testing or verifying it.
+
+ 7. Added the pcre_refcount() auxiliary function.
+
+ 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
+ match before or at the first newline in the subject string. In pcretest,
+ the /f option on a pattern can be used to set this.
+
+ 9. A repeated \w when used in UTF-8 mode with characters greater than 256
+ would behave wrongly. This has been present in PCRE since release 4.0.
+
+10. A number of changes to the pcregrep command:
+
+ (a) Refactored how -x works; insert ^(...)$ instead of setting
+ PCRE_ANCHORED and checking the length, in preparation for adding
+ something similar for -w.
+
+ (b) Added the -w (match as a word) option.
+
+ (c) Refactored the way lines are read and buffered so as to have more
+ than one at a time available.
+
+ (d) Implemented a pcregrep test script.
+
+ (e) Added the -M (multiline match) option. This allows patterns to match
+ over several lines of the subject. The buffering ensures that at least
+ 8K, or the rest of the document (whichever is the shorter) is available
+ for matching (and similarly the previous 8K for lookbehind assertions).
+
+ (f) Changed the --help output so that it now says
+
+ -w, --word-regex(p)
+
+ instead of two lines, one with "regex" and the other with "regexp"
+ because that confused at least one person since the short forms are the
+ same. (This required a bit of code, as the output is generated
+ automatically from a table. It wasn't just a text change.)
+
+ (g) -- can be used to terminate pcregrep options if the next thing isn't an
+ option but starts with a hyphen. Could be a pattern or a path name
+ starting with a hyphen, for instance.
+
+ (h) "-" can be given as a file name to represent stdin.
+
+ (i) When file names are being printed, "(standard input)" is used for
+ the standard input, for compatibility with GNU grep. Previously
+ "" was used.
+
+ (j) The option --label=xxx can be used to supply a name to be used for
+ stdin when file names are being printed. There is no short form.
+
+ (k) Re-factored the options decoding logic because we are going to add
+ two more options that take data. Such options can now be given in four
+ different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
+
+ (l) Added the -A, -B, and -C options for requesting that lines of context
+ around matches be printed.
+
+ (m) Added the -L option to print the names of files that do not contain
+ any matching lines, that is, the complement of -l.
+
+ (n) The return code is 2 if any file cannot be opened, but pcregrep does
+ continue to scan other files.
+
+ (o) The -s option was incorrectly implemented. For compatibility with other
+ greps, it now suppresses the error message for a non-existent or non-
+ accessible file (but not the return code). There is a new option called
+ -q that suppresses the output of matching lines, which was what -s was
+ previously doing.
+
+ (p) Added --include and --exclude options to specify files for inclusion
+ and exclusion when recursing.
+
+11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
+ Hopefully, it now does.
+
+12. Missing cast in pcre_study().
+
+13. Added an "uninstall" target to the makefile.
+
+14. Replaced "extern" in the function prototypes in Makefile.in with
+ "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
+ world, but is set differently for Windows.
+
+15. Added a second compiling function called pcre_compile2(). The only
+ difference is that it has an extra argument, which is a pointer to an
+ integer error code. When there is a compile-time failure, this is set
+ non-zero, in addition to the error test pointer being set to point to an
+ error message. The new argument may be NULL if no error number is required
+ (but then you may as well call pcre_compile(), which is now just a
+ wrapper). This facility is provided because some applications need a
+ numeric error indication, but it has also enabled me to tidy up the way
+ compile-time errors are handled in the POSIX wrapper.
+
+16. Added VPATH=.libs to the makefile; this should help when building with one
+ prefix path and installing with another. (Or so I'm told by someone who
+ knows more about this stuff than I do.)
+
+17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
+ passes PCRE_DOTALL to the pcre_compile() function, making the "." character
+ match everything, including newlines. This is not POSIX-compatible, but
+ somebody wanted the feature. From pcretest it can be activated by using
+ both the P and the s flags.
+
+18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
+
+19. libpcre.pc was being incorrectly installed as executable.
+
+20. A couple of places in pcretest check for end-of-line by looking for '\n';
+ it now also looks for '\r' so that it will work unmodified on Windows.
+
+21. Added Google's contributed C++ wrapper to the distribution.
+
+22. Added some untidy missing memory free() calls in pcretest, to keep
+ Electric Fence happy when testing.
+
+
+
Version 5.0 13-Sep-04
---------------------